1. Field of the Invention
The present invention relates to mining equipment.
More particularly, the invention relates to mine supports.
Still more specifically, the present invention relates to auxiliary walking mine supports.
2. The Prior Art
In all underground mining operations it is essential that the overburden be properly supported, to prevent collapse of the roof. Many advances have been made in this respect. However, despite the modern advances the transitional zone between the roadway (main gallery) and the face continues to be a critical area in this respect.
One of the problems is that the mining equipment used in the roadway (e.g. conveyors) and the mining equipment used at or near the face (e.g. coal-mining machinery) overlaps in this transitional zone, in the sense that it is this zone where the different types of equipment interface with one another. Also, operations are carried out in this zone which are subject to different timing cycles. For example, the mined coal or the like must be transmitted from the face conveyors to the roadway conveyors, the conveyors and/or mining machines must be advanced (i.e. "walk") in accordance with the progress of the mining operation, and packing must be effected.
As a rule, the drives for the mining machines and/or the face conveyors extend into the roadway. This means that as these items of equipment advance along the mine face (and hence also lengthwise of the roadway which extends generally parallel to the mine face), the permanently installed roadway supports must be removed ahead of the advancing equipment and be reinstalled behind it. For the duration of its removal, the overburden must be supported by auxiliary supporting equipment. All of the above must, of course, be accomplished in the most expeditious manner possible, since it must not interfere with such other functions as haulage, movement of mine personnel and mine ventilation.
For purposes of such support it is known to provide auxiliary supporting equipment which, heretofore, was a type that could be clamped, bolted or otherwise connected to the roadway supports. This equipment includes e.g. supporting shields and other elements which are braced from below by pit props. As coal removal progresses along the mine face, this equipment must frequently be disassembled, moved along the mine face to new locations and be reassembled. Given the relative frequency of such moves and the relatively large number of components involved in assembly and disassembly, it is clear that such operations are time-consuming and highly labor-intensive. Moreover, the frequent moves tend to change the equilibrium of the overburden so that disassembly and reassembly of the equipment usually requires the ability to make on-the-spot improvisation to accommodate for unexpected or changing conditions. This, in turn, means that the operations must be carried out by skilled miners, rather than by auxiliary personnel, and makes the whole procedure even more costly. In addition, damage to the various components, as well as to the coal-mining and coal-conveying equipment and to the roadway supporting equipment, is almost unavoidable. This is costly and, in the case of damage to the roadway supports, makes it even more difficult to carry out the assembly and disassembly operations.
The seam area of the face adjacent the roadway (i.e. the aforementioned transitional area) is also the area in which the drive equipment for the coal-mining and coal-conveying machines is located. This is the reason for the need to remove the stationary uprights while this equipment passes through. Because of this it has heretofore been customary to temporarily support this transitional area by means of individual hydraulic pit-props which, in effect, define a kind of travelling buffer zone between the face and the roadway supports. The term "travelling" here denotes the fact that after the mining equipment has passed a given location, the pit-props are moved along with it and in the vacated location the stationary uprights are reinstalled. Again, the release and resetting of these pit-props is carried out manually. Aside from the cost and the loss of time involved, the setting of these props (and the effectiveness of support offered) are dependent upon the skill of the workers, which means again that experienced miners must be used although even in that case there can never be any guarantee that human error might not cause difficulties of a miner, of possibly even catastrophic nature.
Prior attempts to overcome the problems outlined above have not been satisfactory, for a variety of reasons, and an acceptable solution to those problems has heretofore eluded the industry.